1. Field of the Invention
The present invention relates generally to a mobile communication system, and in particular, to a method and system for managing mobility and a security process of an Access Terminal (AT) in a mobile communication system supporting Proxy Mobile Internet Protocol (IP).
2. Description of the Related Art
In conventional mobile communication systems such as 3rd Generation Partnership Project 2 (3GPP2) Code Division Multiple Access (CDMA) 1x and EVolution Data Only (EV-DO) systems, an Access Network (AN) manages radio-related resources, and a Packet Data Serving Node (PDSN), which is a separate entity of a Core Network (CN), performs a procedure associated with packet data communication.
The above-stated conventional mobile communication system provides mobility using Mobile Internet Protocol version 4 (MIPv4) and/or Mobile IPv6 (MIPv6) in the mobile environment of ATs. However, the conventional Mobile IP methods are unsuitable for intact use in an Ultra Mobile Broadband (UMB) scheme, which is an improved 3GPP2 scheme aimed at sending a larger volume of data at a higher transmission rate. Therefore, Proxy Mobile IP (Proxy MIP) is under discussion as one of the schemes capable of efficiently supporting UMB. Meanwhile, not only when an AT moves within the UMB network, but also when the AT moves between networks using different network access technologies, e.g., between the UMB network and a Worldwide Interoperability for Microwave Access (WiMAX) network, there is a need for a scheme capable of efficiently supporting mobility of the AT using Proxy MIP, i.e., the conventional MIPv4 method used in the CDMA 1x or EV-DO system requires a long time for access/call processing. In other words, Mobile IP, compared with Simple IP, can provide mobility, but may suffer from a time delay due to the security process, call processing process, and database management for mobility support, in its access/call processing and security processes. Therefore, there is a need for a technology for resolving these problems.